1 files changed, 67 insertions, 0 deletions

diff --git a/arch/arm26/lib/findbit.S b/arch/arm26/lib/findbit.S
new file mode 100644
index 000000000000..26f67cccc37c
--- /dev/null
+++ b/arch/arm26/lib/findbit.S
@@ -0,0 +1,67 @@
+/*
+ *  linux/arch/arm/lib/findbit.S
+ *
+ *  Copyright (C) 1995-2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 16th March 2001 - John Ripley <jripley@sonicblue.com>
+ *   Fixed so that "size" is an exclusive not an inclusive quantity.
+ *   All users of these functions expect exclusive sizes, and may
+ *   also call with zero size.
+ * Reworked by rmk.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+                .text
+
+/*
+ * Purpose  : Find a 'zero' bit
+ * Prototype: int find_first_zero_bit(void *addr, unsigned int maxbit);
+ */
+ENTRY(_find_first_zero_bit_le)
+                teq     r1, #0  
+                beq     3f
+                mov     r2, #0
+1:              ldrb    r3, [r0, r2, lsr #3]
+                eors    r3, r3, #0xff           @ invert bits
+                bne     .found                  @ any now set - found zero bit
+                add     r2, r2, #8              @ next bit pointer
+2:              cmp     r2, r1                  @ any more?
+                blo     1b
+3:              mov     r0, r1                  @ no free bits
+                RETINSTR(mov,pc,lr)
+
+/*
+ * Purpose  : Find next 'zero' bit
+ * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset)
+ */
+ENTRY(_find_next_zero_bit_le)
+                teq     r1, #0
+                beq     2b
+                ands    ip, r2, #7
+                beq     1b                      @ If new byte, goto old routine
+                ldrb    r3, [r0, r2, lsr #3]
+                eor     r3, r3, #0xff           @ now looking for a 1 bit
+                movs    r3, r3, lsr ip          @ shift off unused bits
+                bne     .found
+                orr     r2, r2, #7              @ if zero, then no bits here
+                add     r2, r2, #1              @ align bit pointer
+                b       2b                      @ loop for next bit
+
+/*
+ * One or more bits in the LSB of r3 are assumed to be set.
+ */
+.found:         tst     r3, #0x0f
+                addeq   r2, r2, #4
+                movne   r3, r3, lsl #4
+                tst     r3, #0x30
+                addeq   r2, r2, #2
+                movne   r3, r3, lsl #2
+                tst     r3, #0x40
+                addeq   r2, r2, #1
+                mov     r0, r2
+                RETINSTR(mov,pc,lr)
+